Needling machine and method for equipping and operating same

Abstract

A needle machine (2) according to the invention comprises a needle bar (8) with a plurality of needles (10), a hold-down device (22) for holding down and a support device (26) for supporting the sheet structure (4), as well as a monitoring device (41, 42) which is configured to monitor the positioning of the plurality of needles (10) relative to the hold-down device (22) and / or to the support device (26). Methods according to the invention include monitoring the positioning of the plurality of needles (10) relative to the hold-down device (22) and / or support device (26) by means of a monitoring device (41, 42) after a needle board (12) has been inserted into the needle machine (2) or during operation of the needle machine (2).

Description

[0001] The present invention relates to a needling machine for needling a textile fabric, such as a fiber web, nonwoven fabric, woven fabric, or scrim. The present invention further relates to a method for loading and a method for operating such a needling machine.

[0002] Needle looms are well known and are described, for example, in Lünenschloss and Albrecht: "Vliesstoffe", Georg-Thieme-Verlag Stuttgart, 1982, pp. 122 to 129 or in Albrecht, Fuchs, Kittelmann: "Vliesstoffe", Wiley-VCH Verlag Weinheim, 2000, pp. 270 ff.

[0003] Typically, a textile fabric, such as a fiber web, nonwoven, woven or scrim, is fed to a needling machine at an inlet and conveyed in a conveying direction to a needling zone. In the area of ​​the needling zone, at least one needle bar with a needle board attached to it is arranged. This needle board is equipped with a large number of needles for consolidating the textile fabric. The needles consolidate the textile fabric by being pierced into the textile fabric at high frequency in a piercing direction and then withdrawn from it again. Those skilled in the art are familiar with a wide variety of needle bar designs, including double-needle machines in which needling is performed from above and below using two needle bars, and needle machines in which the needle bar is also moved in the conveying direction of the textile fabric during the consolidating process.

[0004] Efforts are being made to increase the density of the needles and thus the needling of the textile fabric in order to optimize the properties of the bonded nonwoven. However, this density of the needles is limited due to shape and position tolerances in the manufacture and assembly of the needles, needle boards, hold-down devices, and stitch plates, and the resulting increased risk of collision between the needles and the hold-down devices or stitch plates. In the event of a collision, the needles could break, which represents an unacceptable risk in many applications. In addition, contact between the rapidly moving needles and the hold-down devices and stitch plates can lead to increased wear.

[0005] EP 3 896 207 A1 is known from the prior art and discloses a needling machine for needling a textile fabric. It comprises at least one needle bar arranged in a needling zone and having at least one needle board from which a plurality of needles protrude. A drive device moves the needle bar in a reciprocating stroke. Upper and lower support and guide means for the textile fabric extend in the region of the needling zone and form an intermediate space for the passage of the textile fabric. These support and guide means consist of parallel, tensioned wires which have passage openings for the needles of the needle board and are immovable in the conveying direction of the needling machine.

[0006] It is an object of the present invention to provide a needle machine and a method for equipping and a method for operating such a needle machine which enable high operational reliability and, at the same time, high needle density.

[0007] This object is achieved by the subject matter of independent claims 1 and 13 and 14, respectively. Advantageous embodiments are the subject matter of the dependent claims.

[0008] A needle machine according to the invention for needling a textile fabric comprises a needle bar with a plurality of needles for compacting the textile fabric in a needling zone of the needle machine, a hold-down device for holding down the textile fabric in the needling zone, wherein the hold-down device has a plurality of through-openings for the plurality of needles, a support device for supporting the textile fabric in the needling zone, wherein the support device has a plurality of through-openings for the plurality of needles, and a monitoring device which is configured to monitor the positioning of the plurality of needles relative to the hold-down device and / or the support device.

[0009] In this way, a needle loom is provided in which the positioning of the plurality of needles relative to the hold-down device and / or the support device can be monitored, whereby incorrect positioning of one or more needles can be detected and corrected even at high needle density. Incorrect positioning of needles could lead to contact between these needles and the hold-down device and / or support device during operation of the needle loom, which in turn could result in increased wear or even needle or wire breakage. The risk increases with increasing needle density. The monitoring device can counteract this and increase operational reliability.

[0010] Generally within the scope of the invention, "hold-down device and / or support device" herein means only the hold-down device if the monitoring device is configured to monitor the positioning of the plurality of needles relative to the hold-down device, or only the support device if the monitoring device is configured to monitor the positioning of the plurality of needles only relative to the support device, or both the hold-down device and the support device are meant if the monitoring device is configured to monitor the positioning of the plurality of needles relative to the hold-down device and the support device.

[0011] A gap can be formed between the hold-down device and the support device to allow the textile fabric to pass through the needling zone. The textile fabric passes through the needling zone in a conveying direction and is received in the needling zone between the hold-down device and the support device. Therefore, the hold-down device and the support device are preferably arranged one above the other in a direction perpendicular to the conveying direction.

[0012] In all embodiments, the needling zone preferably extends in the conveying direction over a range of 20 cm to 200 cm, more preferably 25 cm to 100 cm. In all embodiments, the needling zone preferably extends transversely to the conveying direction over a range of 200 cm to 500 cm, more preferably 250 cm to 400 cm.

[0013] The needle bar can perform an oscillating stroke movement that has at least one component in a piercing direction perpendicular to the conveying direction. This allows the plurality of needles to penetrate into the textile fabric and then be withdrawn from it again. It is also conceivable for the plurality of needles to have a movement component in the conveying direction, so that the needles are moved with the textile fabric in the conveying direction while engaging with it. By superimposing the stroke movement in the piercing direction and the movement in the conveying direction, the needle tips of the plurality of needles can describe an elliptical or circular trajectory.

[0014] In principle, the needle loom can also have more than one needle bar, whereby the needle bars can be arranged in a known manner one behind the other in the conveying direction and / or next to one another transversely to the conveying direction and transversely to the piercing direction. The features described herein apply analogously to a plurality of needle bars.

[0015] To drive the needle bar, the needle machine can comprise a drive device configured to impart at least one oscillating stroke movement to the at least one needle bar. For example, the drive device comprises a drive shaft on which a connecting rod is eccentrically mounted, which in turn is connected, in particular pivotally connected, to the at least one needle bar.

[0016] To allow the plurality of needles to penetrate the textile fabric, at least the hold-down device typically has through-openings for the needles. Furthermore, the support device also has through-openings for the needles, for example, if the plurality of needles are intended to penetrate the textile fabric or if the textile fabric is needled from above and below. It is understood that with increasing needle density, the clearance between the plurality of needles in the through-openings is reduced, thereby increasing the risk of needle contact with the hold-down device and / or the support device.

[0017] Monitoring the positioning of the plurality of needles relative to the hold-down device and / or the support device may comprise determining the position of the plurality of needles relative to the hold-down device and / or the support device. However, it may be sufficient to determine whether the plurality of needles has a positioning that is correct or incorrect. For example, the positioning of each needle may be correct as long as the needle passes through the through-openings in the hold-down device and / or the support device, and incorrect as soon as the needle contacts the hold-down device and / or the support device. Determining an exact position of each needle is not required for this purpose, so the monitoring device can be of simple design.It is particularly relevant to position the large number of needles in a transverse direction perpendicular to the conveying direction and perpendicular to the piercing direction, since this is where the least free space is usually available.

[0018] In one embodiment, the monitoring device can be configured to detect an approach of one of the plurality of needles to the hold-down device and / or the support device. In this way, an approach of a needle to the hold-down device and / or the support device can be responded to at an early stage, before contact can even occur. The approach can be determined by a reduction in the distance of a needle from the hold-down device and / or support device or by a distance of a needle from a predetermined position or a deviation from this predetermined position. An approach in the transverse direction is again particularly relevant.

[0019] In a preferred embodiment, the monitoring device is configured to detect contact between a needle of the plurality of needles and the hold-down device and / or the support device. Contact between a needle of the plurality of needles and the hold-down device and / or the support device can be detected relatively easily and reliably, so that the monitoring device can be implemented easily and cost-effectively while functioning reliably.

[0020] Preferably, the monitoring device is configured to output an optical, acoustic, and / or electrical signal upon contact of one of the plurality of needles with the hold-down device and / or the support device. The electrical signal can be an analog or digital signal that can be transmitted, for example, to a control unit. This reliably alerts an operator of the needle-punching machine to the contact so that appropriate measures can be taken.

[0021] It is also conceivable that, in the event of contact, the needle loom, in particular a lifting movement of the needle bar, is stopped, for example by triggering an emergency stop. Consequently, the monitoring device is then configured to cause the needle loom to stop.

[0022] The monitoring device can be an optical monitoring device, which, for example, comprises at least one camera, light barrier, laser, or the like. An optical monitoring device is particularly suitable for detecting a needle that is located in an undesired area or that is leaving this area.

[0023] Additionally or alternatively, the monitoring device can be an acoustic monitoring device, which comprises, for example, a sound transducer, such as a microphone. Upon contact of a needle with the hold-down device and / or the support device, detectable sound waves are generated. In particular, a frequency can be recorded. Furthermore, the monitoring device can, additionally or alternatively, comprise a vibration monitoring device. Upon contact of a needle with the hold-down device and / or the support device, the latter is at least partially set into vibration, which is detectable.

[0024] In a particularly preferred embodiment, the monitoring device is an electrical monitoring device, which comprises, for example, a resistance detection device, a conductive detection device, an inductive detection device, or a capacitive detection device. The electrical monitoring device preferably uses low voltage, in particular a voltage of maximum 25 V, more preferably of maximum 10 V. This makes the monitoring device as safe as possible for the operator. In one embodiment, the hold-down and / or support device can be supplied with a digitally coded signal, and the monitoring device is configured to evaluate the signal. For example, the signal can be characteristic of a specific element or a specific section of the hold-down and / or support device.

[0025] A conductive detection device and a resistance detection device are particularly suitable for detecting contact of a needle from the plurality of needles with the hold-down device and / or the support device. An inductive or capacitive detection device is particularly suitable for detecting an approach of a needle from the plurality of needles to the hold-down device and / or the support device.

[0026] The electrical monitoring device is preferably configured such that, upon contact of one of the plurality of needles with the hold-down device and / or the support device, an electrical circuit comprising a voltage source is closed. For this purpose, the plurality of needles and the hold-down device and / or the support device are configured to be at least partially electrically conductive. In this way, upon contact of a needle with the hold-down device and / or the support device, an electrical signal is automatically generated, which can be used, for example, for the optical and / or acoustic signal or digitally encoded.

[0027] In a first embodiment, each of the needles of the plurality of needles is electrically conductively connected to a ground or the voltage source, in particular to the negative pole of the voltage source. In addition, the hold-down device or the support device can be electrically conductively connected to the voltage source. If one needle of the plurality of needles then contacts the one of the hold-down device and support device that is connected to the voltage source, the circuit is closed and an electric current flows. However, it is also conceivable that, for example, only one needle of a group of needles, for example of a needle module, is connected to the voltage source. In this way, it can be concluded from the one needle that the entire group is incorrectly positioned.

[0028] In the first embodiment, each needle can be individually connected to the voltage source. For this, the individual needles would have to be mounted in the needle board, electrically insulated from one another, and individually connected to the voltage source, which is possible, for example, using conductor tracks. However, groups of the plurality of needles are preferably connected to a common electrically conductive contact element, which in turn is electrically conductively connected to the voltage source. Each group of needles comprises a plurality of needles. This reduces the complexity and required installation space.

[0029] For example, each needle of the plurality of needles has a tip and a head opposite the tip. At least one electrically conductive contact element is provided on the needle bar or needle board, and the plurality of needles is mounted on the needle bar or needle board such that the heads of the needles are in contact with the at least one conductive contact element.

[0030] In general, the needles are preferably arranged in needle modules, each needle module having a module carrier and a plurality of needles. The plurality of needles is connected to the module carrier in a head-side section, for example, injected into it, so that the tips of the plurality of needles protrude from the module carrier in one direction. The module carrier is preferably formed from a non-conductor, in particular from plastic. Each needle module can have a single longitudinal row of needles or have multiple longitudinal rows of needles. To enable electrical contact, the heads of the plurality of needles are preferably also exposed or protrude from the module carrier, which is particularly relevant for the first embodiment of the monitoring device.

[0031] The needle modules can in turn be received in recesses or supports of at least one needle board and fastened there. Preferably, several needle modules are arranged one behind the other in the transverse direction, with the rows of needles of the needle modules aligned in the conveying direction. The needle modules can be displaceable in the recesses or supports and can be fixed, e.g. clamped, in the desired position. Each needle board is in turn fixed to the needle bar. In the first embodiment of the monitoring device, the at least one electrically conductive contact element can be inserted into the recess or the support of the needle board or formed integrally with them, such that it is in contact with the needles of inserted needle modules.

[0032] Arranging the needles in needle modules offers several advantages. The needle modules can be arranged slidably within the needle board, allowing for variable stitch patterns and needle board configurations. Furthermore, the needle modules can be aligned relative to the hold-down device and the support device to avoid contact with them. Furthermore, the needle modules can be arranged so closely together that no gap remains between individual needle modules.

[0033] In a second embodiment, the hold-down device and the support device are each at least partially electrically conductive and electrically connected to the voltage source. Each needle is preferably electrically conductive. In this case, the plurality of needles does not need to be separately connected to ground or the voltage source. Rather, a needle that contacts the hold-down device and the support device closes the circuit, and an electrical current flows. Electrical contact between the hold-down device and the support device and the voltage source is generally easier and more reliable to implement than contact between the plurality of needles.

[0034] In order to enable a high needle density, it is preferred that the hold-down device and the support device each independently comprise a plurality of wires for holding down or supporting the textile fabric. As a result, the needles of the plurality of needles can be arranged at a short distance from one another, while the wires can extend between the needles to fulfill their hold-down or support function. For this purpose, it is further advantageous if the plurality of wires of the hold-down device are arranged in the needling zone in a plane that is parallel to the conveying direction and the transverse direction. Further advantageously, the plurality of wires of the support device are arranged in the needling zone in a plane that is parallel to the conveying direction and the transverse direction or parallel to the plane of the plurality of wires of the hold-down device.Through-openings for the plurality of needles are formed between the wires of the hold-down device, and through-openings for the plurality of needles are also formed between the wires of the support device.

[0035] To achieve the simplest possible design, the wires of the plurality of wires are preferably mounted such that they are immobile in the conveying direction of the needle-punching machine. For example, each wire has two ends that are fixed in the needle-punching machine. During operation of the needle-punching machine, the plurality of wires are preferably arranged stationary.

[0036] To form the electrical monitoring device, each of the plurality of wires of the hold-down device and / or the support device can be connected to a voltage source, as described above. This can be one and the same voltage source for all wires of the hold-down device and the support device, a voltage source each for the wires of the hold-down device and for the wires of the support device, or multiple voltage sources for each group of wires of the hold-down device and / or the support device.

[0037] In all embodiments, the wires are preferably electrically conductive, preferably as metal wires. The wires can be arranged in such a way that they are electrically insulated from one another.

[0038] The plurality of wires are preferably arranged parallel to one another and parallel to the conveying direction of the needle-punching machine in the needling zone, and are spaced apart from one another in the transverse direction. Consequently, a passage opening for the needles is formed between every two adjacent wires. By aligning the wires parallel to the conveying direction, the passage openings also extend parallel to the conveying direction, allowing the plurality of needles a movement component in the conveying direction. However, the plurality of wires can also be aligned obliquely to the conveying direction.

[0039] During the oscillating movement of the plurality of needles, the needles each pass between two adjacent wires of the plurality of wires. In other words, when the plurality of needles is lowered, each needle is arranged in a passage opening between two wires.

[0040] In a preferred embodiment, the needles are arranged in rows, for example, in the needle modules described above, wherein the rows of needles are aligned parallel to a direction of extension of the plurality of wires. Preferably, each row of needles then enters between two adjacent wires of the plurality of wires. The pitch of the rows of needles preferably corresponds to the pitch of the plurality of wires. However, it would also be conceivable, for example, to omit individual rows or modules of needles.

[0041] In all embodiments, a pitch of the plurality of wires is preferably between 1.4 mm and 4 mm, more preferably between 1.8 mm and 3.2 mm, even more preferably between 2.2 mm and 2.8 mm.

[0042] Preferably, the plurality of wires has a diameter between 0.4 mm and 2 mm, preferably between 0.5 mm and 1.5 mm, more preferably between 0.6 mm and 1.2 mm. The small diameters of the wires promote a high needle density, thus a particularly tight stitch pattern and a particularly uniformly solidified end product.

[0043] In a preferred embodiment, the needles are arranged at a density of at least 500 needles / dm 2 , preferably at least 1,000 needles / dm 2 , more preferably at least 1,500 needles / dm 2 . Such high needle densities lead to a particularly uniform stitch pattern in the consolidated end product.

[0044] The plurality of needles has a diameter at the needle head that is preferably between 1.0 mm and 2.0 mm, more preferably between 1.2 mm and 1.8 mm. The plurality of needles has a diameter at the needle tip or in a working area of ​​the needle that is preferably at most between 0.3 mm and 1 mm, more preferably between 0.4 mm and 0.6 mm. The working area of ​​the needles is the area that penetrates the textile fabric or between the support and hold-down device. If the needles have a cross-sectional shape in the working area that is not circular, the diameter can be determined using a circumcircle.

[0045] In an embodiment where the wire pitch is 2.4 mm, the wire diameter is 0.8 mm, and the needle diameter is 0.5 mm, a clearance of 0.55 mm remains on each side of the needles to the nearest wire. This illustrates the high risk of contact between the needles and the wires and the resulting importance of positioning the needles as precisely as possible relative to the wires.

[0046] In a preferred embodiment, each wire of the plurality of wires is assigned an optical display, in particular an LED, to which the wire is electrically connected such that the optical display outputs the optical signal upon contact of a needle of the plurality of needles with the wire. This applies to all embodiments of the needling machine that comprise a plurality of wires and whose monitoring device is configured to output an optical signal. If an optical display is assigned to each wire, contact between a needle and a wire can be easily located because the affected needle is arranged along the wire whose optical display outputs the optical signal, and thus the affected row of needles can be identified. However, locating an affected needle without such a display would be difficult due to the high number and density of needles.Of course, it would also be possible to assign an optical display to several wires in order to reduce the complexity of the monitoring device and the required installation space.

[0047] The monitoring device can further be configured to maintain the output signal, in particular the optical signal, after contact. This allows the affected row of needles to be identified even if contact is no longer present, for example due to a lifting movement of the needle bar. For this purpose, the monitoring device can comprise a storage device, such as a capacitor. For example, a contact can be stored by means of a transistor circuit that can be activated and deactivated by a control unit. It is also conceivable that the contact and the resulting current flow connect the optical display to another voltage source that maintains the optical signal. For example, electrical contact can be maintained by means of the transistor circuit.

[0048] In principle, the needle machine and / or the monitoring device can comprise a control unit, such as a programmable logic controller. The control unit can then also comprise the memory device or perform the corresponding switching, whereby the optical signal is retained when remanence is activated. Furthermore, detected contacts can be transmitted to the control unit in analog and / or digital form, for example in the form of an electrical signal provided by the monitoring device. This enables the output of further signals to the operator, e.g., via a human-machine interface of the needle machine, and further analysis.

[0049] A method according to the invention for loading a needle machine comprises the following steps: Inserting a needle board into the needle machine; moving the needle board at least in a piercing direction oriented perpendicular to a conveying direction of the needle machine in a needling zone, wherein the plurality of needles pass through a plurality of through-openings in a hold-down device and / or a support device of the needle machine; and monitoring a positioning of the plurality of needles relative to the hold-down device and / or support device by means of a monitoring device.

[0050] In this way, a method is provided in which the positioning of the plurality of needles relative to the hold-down device and / or the support device can be monitored, whereby incorrect positioning of one or more needles can be detected and corrected even at high needle density. Incorrect positioning of needles can lead to contact of these needles with the hold-down device and / or support device during operation of the needle loom, which in turn can result in increased wear or even needle or wire breakage. The risk increases with higher needle density. Thanks to the monitoring by the monitoring device, this can be counteracted and operational reliability increased.

[0051] In principle, the method can be used for loading the needle-punching machine according to the invention described herein. All features and advantages described with regard to the needle-punching machine therefore apply analogously to the method, and vice versa.

[0052] The needle board is preferably equipped with a plurality of needle modules, each comprising a plurality of needles. Preferably, the plurality of needle modules is already secured to the needle board upon insertion, and the needle board is secured to the needle bar after insertion. In this state, the plurality of needles should be correctly positioned. Before inserting the needle board into the needle loom, the method can comprise inserting the plurality of needle modules into the needle board. For this purpose, several needle modules can be inserted one behind the other in the transverse direction into a recess or a carrier of the needle board. The needle modules can be inserted into the needle board outside the needle loom.

[0053] Moving the needle board in the insertion direction can be performed during the setup or loading of the needle loom before its actual operation. In particular, single or a few strokes of the needle bar can be performed to check the alignment of the multiple needles or multiple needle modules. This allows immediate intervention and, if necessary, correction of the alignment before the needle loom starts operation and damage can occur.

[0054] A method according to the invention for operating a needle machine comprises the following steps: Moving a textile fabric in a conveying direction through a needling zone of the needling machine, wherein the textile fabric is received in the needling zone between a support device and a hold-down device; compacting the textile fabric by oscillatingly moving a plurality of needles at least in a piercing direction that is oriented perpendicular to a conveying direction of the needling machine in a needling zone, the plurality of needles passing through a plurality of passage openings in the hold-down device and / or the support device; monitoring a positioning of the plurality of needles relative to the hold-down device and / or the support device by means of a monitoring device.

[0055] In this way, a method is provided in which the positioning of the plurality of needles relative to the hold-down device and / or the support device can be monitored, whereby incorrect positioning of one or more needles can be detected and corrected even at high needle density. Incorrect positioning of needles can lead to contact of these needles with the hold-down device and / or support device during operation of the needle loom, which in turn can result in increased wear or even needle or wire breakage. The risk increases with higher needle density. Thanks to the monitoring by the monitoring device, this can be counteracted and operational reliability increased.

[0056] In principle, the method can be used to operate the needle-punching machine according to the invention described herein. All features and advantages described with respect to the needle-punching machine therefore apply analogously to the method, and vice versa.

[0057] In both methods, monitoring the positioning of the plurality of needles preferably comprises detecting contact between one of the plurality of needles and the hold-down device and / or the support device. For example, upon contact, an electrical circuit is closed. The methods may then further comprise outputting the optical and / or acoustic and / or electrical signal, as described with respect to the electrical monitoring device. The electrical signal may be an analog or digital signal, which may be transmitted, for example, to the control unit.

[0058] Further features and advantages of the present invention will become apparent from the following description with reference to the drawings. Fig. 1 shows a schematic side view of the essential components of a needle loom; Fig. 2 shows a section of the needling zone of the needle loom according to Fig. 1 in perspective view; Fig. 3a schematically shows a first embodiment of a monitoring device of the needle machine according to Fig. 1 and 2 in perspective view; Fig. 3b shows a circuit diagram of the monitoring device according to Fig. 3a ; Fig. 4a shows schematically a second embodiment of a monitoring device of the needle machine according to Fig. 1 and 2 in perspective view; Fig. 4b shows a circuit diagram of the monitoring device according to Fig. 4a ; and Fig. 5 shows a detailed view of a section of the monitoring device.

[0059] In Fig. 1 the essential components of a needling machine 2 are shown schematically in a side view. Basically, in the needling machine 2, a textile fabric 4, such as a fiber web, a nonwoven fabric, a woven fabric or a scrim, is conveyed in a conveying direction F through a needling zone 6, in which the textile fabric 4 is consolidated. For this purpose, the needling machine 2 comprises at least one needle bar 8 with a plurality of needles 10. For example, a needle board 12 can be equipped with the plurality of needles 10 and fixed to the needle bar 8. Optionally, the needling machine 2 can comprise a plurality of needle bars 8a, 8b, 8c, 8d, as shown. The needle bars 8a and 8b are arranged one behind the other in the conveying direction F.In addition, the illustrated embodiment is a double-needle machine in which needling also takes place from below by means of the needle bars 8c and 8d, which in turn are arranged one behind the other in the conveying direction F. The basic structure of needle machines 2 and possible variations thereof are known to the person skilled in the art.

[0060] To consolidate the textile fabric 4, the plurality of needles 10 are inserted into the textile fabric 4 at high frequency, at least parallel to a penetration direction E, and then withdrawn from it again. For this purpose, the needle bar 8 is set in motion in a known manner by means of a drive device 14. The drive device 14 can comprise a drive shaft 16 on which a connecting rod 18 is eccentrically mounted. The connecting rod 18, in turn, is connected to the needle bar 8, preferably by means of an articulated connection. If multiple needle bars 8a, 8b are provided, they can be connected by means of a bridge 20 to which the connecting rod 18 is connected.

[0061] By appropriately designing the drive device 14 and / or guiding the needle bar arrangement 8, 20, a movement path of the plurality of needles 10 can be adjusted during the lifting movement of the needle bar 8. For example, the needles 10 can move up and down exclusively parallel to the piercing direction E. However, it is also possible for this movement to be superimposed with a movement component parallel to the conveying direction F, so that the needles 10 perform an elliptical or circular movement. In particular, the needles 10 then move in the conveying direction F during engagement with the textile fabric 4. Various designs of needle-punching machines that implement the different movement patterns of the needles are known to those skilled in the art, and the present invention is not limited to a specific one of these designs.

[0062] In order to enable the penetration of the plurality of needles 10 into the textile fabric 4 and at the same time to prevent significant quantities of fibers from being pulled out of the textile fabric 4 or the entire textile fabric from being lifted when the needles 10 are pulled out of the fabric 4, the needling machine 2 comprises a hold-down device 22 for holding down the textile fabric 4 in the needling zone 6. The hold-down device 22 has through-openings 24 (see Fig. 2 ) through which the needles 10 can pass. A support device 26 for supporting the textile fabric 4 in the needling zone 6 can also have passage openings 28 for the needles 10, for example when the needles 10 of the upper needle bars 8a, 8b completely penetrate the textile fabric 4 or in the case of double-needle machines.

[0063] The hold-down device 22 and the support device 26 are described with reference to Fig. 2 described in more detail, which shows a section of the needling zone 6 in a detailed view. In principle, the hold-down device 22 and the support device 26 can be designed as hold-down or throat plates with through-openings 24, 28 in the form of round or slot-shaped recesses, as is generally known. In the illustrated embodiment, the hold-down device 22 comprises a plurality of (upper) wires 30 and the support device 26 comprises a plurality of (lower) wires 32. The plurality of upper wires 30 is preferably arranged in a first plane in the needling zone 6 and the plurality of lower wires 32 is preferably arranged in the needling zone 6 in a second plane which is aligned parallel to and spaced from the first plane.As a result, a gap 34 is formed between the plurality of upper wires 30 and the plurality of lower wires 32, in which gap the textile fabric 4 is conveyed in the needling zone 6.

[0064] The plurality of wires 30, 32 are preferably aligned parallel to the conveying direction F. In a transverse direction Q, the upper wires 30 are spaced apart from one another, and the lower wires 32 are spaced apart from one another. As a result, a passage opening 24, 28 for a needle 10 or a row of needles 10 is formed between each two adjacent wires 30, 32 in the transverse direction Q. Due to the extension of the plurality of wires 30, 32 in the conveying direction F, the passage openings 24, 28 allow movement of the needles 10 in the conveying direction F.

[0065] The needles 10 are preferably arranged in needle modules 36, each needle module 36 having a module carrier 38 and a plurality of needles 10. The plurality of needles 10 is connected to the module carrier 38 in a head-side section, for example, injected into it. The tips 10a of the needles 10 protrude from the module carrier 38 parallel to the piercing direction E. Each needle module 36 preferably has a single row of needles 10, but can also have several longitudinal rows of needles 10. The plurality of needles 10 of all needle modules 36 then forms the plurality of needles 10 on the needle bar 8. This applies generally within the scope of the invention.

[0066] The needle modules 36 can in turn be accommodated in supports 40 of a needle board 12. Preferably, a plurality of needle modules 36 are arranged one behind the other in the transverse direction Q, so that the rows of needles 10 are aligned in the conveying direction F. The needle modules 36 can be inserted into the support 40 in the transverse direction Q and can be displaced relative to one another there for alignment with the hold-down device 22 and the support device 26. Before operation of the needle machine 2, the needle modules 36 are secured in the supports 40. Each needle board 12 can have a plurality of rows of needle modules in supports 40, which are arranged one behind the other in the conveying direction F, as in Fig. 1 shown.

[0067] The needle machine 2 further comprises a monitoring device 41, 42, which is configured to monitor the positioning of the plurality of needles 10 relative to the hold-down device 22 and / or the support device 26. The monitoring device 41 can, for example, be an optical monitoring device 41, which is configured to optically monitor the positioning of the plurality of needles 10 in the needling zone 6, as shown in Fig. 1 For this purpose, the monitoring device 41 can comprise a camera, a laser, a light barrier, or the like. However, the monitoring device is preferably designed as an electrical monitoring device 42 and is particularly configured to detect contact between a needle 10 of the plurality of needles 10 and the hold-down device 22 and / or the support device 26.

[0068] The electrical monitoring device 42 is described below by way of example using a first embodiment according to Fig. 3a, 3b and by means of a second embodiment according to Fig. 4a, 4b described. In the Fig. 3a and 4a For the sake of clarity, only a few wires 30, 32 and a few needle modules 36 are shown in the needling zone 6 as representative of the previously described structure of the needling machine 2. The principle explained therein can be scaled as desired. It is understood that the described features and advantages are also applicable to embodiments of the needling machine 2 in which the hold-down device 22 and the support device 26 are not formed by wires 30, 32.

[0069] The Fig. 3a und 3b The arrangement shown is equally applicable to the hold-down device 22 and to the support device 26. According to the first embodiment, each needle 10 of the plurality of needles 10 is electrically connected to a voltage source 44. In addition, the hold-down device 22 or the support device 26 is electrically connected to the voltage source 44. If a needle 10 of the plurality of needles 10 now contacts the hold-down or support device 22, 26, the circuit is closed and an electric current flows.

[0070] More precisely, each wire 30a, 30b, 30c of the hold-down device 22 or each wire 32a, 32b, 32c of the support device 26 is preferably connected to the voltage source 44. In addition, each needle module 36a, 36b, 36c is connected to the voltage source 44. The heads 10b of the needles 10 can be exposed or protrude from the module carrier 38 and contact an electrically conductive contact element 46, which in turn is connected to the voltage source 44. The contact element 46 can, for example, be inserted into the carriers 40 on the needle board 12 or be formed integrally with them. Preferably, at least one contact element 46 is provided for each carrier 40 and thus for each row of needle modules 36. In the illustrated case, the needle 10c touches the wire 30a, 32a, for example because it is bent, and thereby closes the electrical circuit.

[0071] In principle, the monitoring device 41, 42 can be configured to emit a visual and / or acoustic signal upon contact of a needle 10 with the hold-down device 22 and / or the support device 26. For this purpose, the monitoring device 41, 42 can comprise a visual display 48, for example in the form of an LED. In the illustrated embodiment, each wire 30a, 30b, 30c or 32a, 32b, 32c is assigned an LED 48a, 48b, 48c. If the circuit is closed on a wire, here on wire 30a, 32a, the corresponding LED 48a lights up and thereby emits the visual signal. The operator of the needle loom 2 can thereby determine which wire is in contact with one or more needles 10, for example due to a defective needle 10 or incorrect alignment of the needle 10, and thus locate the corresponding needle(s).

[0072] In Fig. 3b The needle modules 36a, 36b, 36c are shown as equivalent resistance. According to the circuit diagram in Fig. 3b Furthermore, each LED 48a, 48b, 48c can be assigned a series resistor 50a, 50b, 50c.

[0073] According to the second embodiment, the hold-down device 22 and the support device 26 are each connected to the voltage source 44. In this embodiment, the plurality of needles 10 need not be separately connected to the voltage source 44. The heads 10b of the needles 10 can therefore also be completely accommodated in the module carrier 38. If a needle 10 of the plurality of needles 10 contacts the hold-down device 22 and the support device 26, it thereby closes the circuit and an electric current flows.

[0074] More specifically, each wire 30a, 30b, 30c of the plurality of wires 30 of the hold-down device 22 as well as each wire 32a, 32b, 32c of the plurality of wires 32 of the support device 26 is preferably connected to the voltage source 44. In the illustrated case, the needle 10c, for example, touches the wire 30c and the wire 32c, thereby closing the circuit.

[0075] An optical display 48 can also be provided in the second embodiment, with each upper wire 30a, 30b, 30c of the hold-down device 22 being assigned an LED 48a, 48b, 48c, and each lower wire 32a, 32b, 32c of the support device 26 being assigned an LED 48d, 48e, 48f. Therefore, the LEDs 48c and 48f would emit an optical signal. It would also be conceivable that a needle 10c is bent or a needle module 36 is misaligned in such a way that the needle 10c contacts the wire 30c of the hold-down device 22 and the wire 32b of the support device 26. This would also be apparent to the operator through the LEDs 48c and 48e then illuminating.

[0076] In the circuit diagram according to Fig. 4b The needle modules 36a, 36b, 36c are represented by equivalent resistors, on both sides of which extend the upper wires 30 and the lower wires 32, respectively. Each LED 48a-f can be assigned a series resistor 50a-f.

[0077] In Fig. 5 is a detailed view of the hold-down device 22 and the support device 26 in the area of ​​an inlet 52 of the textile fabric 4 (see Fig. 1 ). Analogously, the needle loom 2 could be designed with an outlet 54. At the inlet 52 and the outlet 54, the plurality of wires 30 of the hold-down device 22 are deflected upwards and the plurality of wires 32 of the support device 26 are deflected downwards. In the region of the inlet 52, the plurality of upper wires 30 and the plurality of lower wires 32 increasingly approach one another in the conveying direction F in order to form the intermediate space 34 for receiving the textile fabric 4. The plurality of wires 30, 32 can be guided essentially arbitrarily outside the inlet 52 and the outlet 54, so that more installation space is available, for example for a tensioning device 56 for the wires 30, 32.

[0078] The monitoring device 41, 42 can comprise one or more circuit boards 58, one of which is described as an example. As shown, several wires 32a-h of the support device 26 can run to a circuit board 58 and be electrically connected there to an LED 48 each. In addition, the voltage source 44 can be connected to the wires 32a-h via the circuit board 58. It is also conceivable for further control and / or evaluation electronics to be arranged on the circuit board 58, for example to count the number of contacts of needles 10 with a wire 32a-h assigned to the respective circuit board 58 or to maintain the optical signal of the respective LED 48 after contact of a needle 10 with one of the wires 32a-h, even if the contact no longer exists.

[0079] Further embodiments within the scope of the invention will be apparent to those skilled in the art based on the description of preferred embodiments contained herein.

Claims

1. A needling machine (2) for needling a textile fabric (4), wherein the needling machine (2) comprises: a needle beam (8) with a plurality of needles (10) for compressing the textile fabric (4) in a needling zone (6) of the needling machine (2); a hold-down device (22) for holding down the textile fabric (4) in the needling zone (6), wherein the hold-down device (22) has a plurality of passage openings (24) for the plurality of needles (10); and a support device (26) for supporting the textile fabric (4) in the needling zone (6), wherein the support device (22) has a plurality of passage openings (28) for the plurality of needles (10); characterized in that the needling machine (2) also comprises: a monitoring device (41, 42),which is set up for monitoring the positioning of the plurality of needles (10) relative to the hold-down device (22) and / or to the support device (26).

2. The needling machine (2) according to claim 1, characterized in that the monitoring machine (41, 42) is set up to detect a contact between one needle (10) from among the plurality of needles (10) and the hold-down device (22) and / or the support device (26).

3. The needling machine (2) according to claim 2, characterized in that the monitoring device (41, 42) is set up to output an acoustic and / or an electric signal, wherein the electric signal is preferably an analog or digital signal.

4. The needling machine (2) according to one of claims 1 to 3, characterized in that the monitoring device (41, 42) is an electric monitoring device (42), which preferably comprises a resistance detection device, a conductive detection device, an inductive detection device or a capacitive detection device.

5. The needling machine (2) according to claim 4, characterized in that the monitoring device (42) is designed in such a way that a circuit comprising a voltage source (44) is closed given contact between one needle (10) from among the plurality of needles (10) and the hold-down device (22) and / or the support device (26).

6. The needling machine (2) according to claim 5, characterized in that each needle from among the plurality of needles (10) is electrically conductively connected with a ground or the voltage source (44).

7. The needling machine (2) according to claim 6, characterized in that a respective group of needles (10) from among the plurality of needles (10) is connected with a shared, electrically conductive contact element (46), which is electrically conductively connected with the ground or the voltage source (44).

8. The needling machine (2) according to claim 6, characterized in that the hold-down device (22) and the support device (26) are electrically conductive in design, and each electrically conductively connected with the voltage source (44).

9. The needling machine (2) according to one of claims 1 to 3, characterized in that the monitoring device (41, 42) is an optical monitoring device.

10. The needling machine (2) according to one of the preceding claims, characterized in that the hold-down device (22) and / or the support device (26) each comprise a majority of wires (30, 32) for holding down or supporting the textile fabric (4), wherein the passage openings (24, 28) between the wires (30, 32) of the majority of wires (30, 32) are designed for the plurality of needles (10).

11. The needling machine (2) according to claim 10 depending on claim 3, characterized in that each wire (30, 32) from among the majority of wires (30, 32) has allocated to it an optical display (48), in particular an LED, with which the wire (30, 32) is electrically conductively connected in such a way that the optical display (48) outputs the optical signal given contact between a needle from among the plurality of needles (10) and the wire (30, 32).

12. The needling machine (2) according to claim 11, characterized in that the monitoring device (41, 42) is set up to maintain the optical signal following the contact.

13. A method for loading a needling machine (2) comprising the following steps: using a needle board (12) in the needling machine (2); and moving the needle board (12) in at least an insertion direction (E) aligned perpendicular to a conveying direction (F) of the needling machine (2) in a needling zone (6), wherein the majority of needles (10) pass through a majority of passage openings (24) in a hold-down device (22) and / or a majority of passage openings (28) in a support device (26) of the needling machine (2); characterized in that the method further comprises: monitoring a positioning of the majority of needles (10) relative to the hold-down device (22) and / or support device (26) by means of a monitoring device (41, 42).

14. A method for operating a needling machine (2) comprising the following steps: moving a textile fabric (4) in a conveying direction (F) through a needling zone (6) of the needling machine (2), wherein the textile fabric (4) is accommodated in the needling zone (6) between a support device (26) and a hold-down device (22); and compressing the textile fabric (4) via the oscillating motion of a plurality of needles (10) in at least an insertion direction (E) aligned perpendicular to the conveying direction (F) in the needling zone (6), wherein the plurality of needles (10) passes through a majority of passage openings (24, 28) in the hold-down device (22) and / or in the support device (26); characterized in that the method further comprises: monitoring a positioning of the majority of needles (10) relative to the hold-down device (22) and / or support device (26) by means of a monitoring device (41, 42).

15. The method according to claim 13 or 14, characterized in that monitoring involves detecting a contact between a needle (10) from among the plurality of needles (10) and the hold-down device (22) and / or the support device (26), and the method further comprises the following step: outputting an acoustic, optical, and / or electric signal via the monitoring device (41, 42) if the monitoring device (41, 42) detects a contact, wherein the electric signal is preferably an analog or digital signal.

Images